Automatic Gain Control Patents (Class 375/345)
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Patent number: 8724726Abstract: An automatic gain control apparatus and method for a compressed mode in a MIMO system are provided. The method includes determining power at a first frequency band using a first receiver, simultaneously determining power at a second frequency band using a second receiver in a compressed mode, if the second receiver changes a power determination frequency band into the first frequency band, correcting the power determination value of the first receiver, and applying the corrected power determination value of the first receiver to the second receiver.Type: GrantFiled: October 28, 2009Date of Patent: May 13, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Hung-Su Park, Shin-Woo Kang, Soo-Bok Yeo, Ki-Hwan Jeon, Joo-Kwang Kim, Sung-Chul Han
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Patent number: 8725099Abstract: In one embodiment, the present invention includes a mixer circuit to receive and generate a mixed signal from a radio frequency (RF) signal and a master clock signal, a switch stage coupled to an output of the mixer circuit to rotatingly switch the mixed signal to multiple gain stages coupled to the switch stage, and a combiner to combine an output of the gain stages.Type: GrantFiled: October 30, 2012Date of Patent: May 13, 2014Assignee: Silicon Laboratories Inc.Inventors: Aslamali A. Rafi, Alessandro Piovaccari
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Patent number: 8724759Abstract: The current application is directed to maintaining the correct number of symbols in a protocol frame in a digital communications receiver, to prevent catastrophic failure due to dynamic multipath or cycle slips. Timing recovery and framing are coherent, facilitated by placing channel estimation directly into a larger timing recovery loop.Type: GrantFiled: May 7, 2012Date of Patent: May 13, 2014Assignee: I Berium Communications, Inc.Inventors: Raúl Alejandro Casas, Stephen Biracree, Anand Mahendra Shah, Slobodan Simovich, Thomas Joseph Endres
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Patent number: 8718164Abstract: Techniques for transmitting pilot and for processing received pilot to obtain channel and interference estimates are described. A terminal may generate pilot symbols for a first cluster in a time frequency block based on a first sequence and may generate pilot symbols for a second cluster in the time frequency block based on a second sequence. The first and second sequences may include common elements arranged in different orders and may be considered as different versions of a single sequence. The terminal may transmit the pilot symbols in their respective clusters. A base station may obtain received pilot symbols from multiple clusters in the time frequency block. The base station may form each of multiple basis vectors with multiple versions of the sequence assigned to the terminal and may process the received pilot symbols with the multiple basis vectors to obtain a channel estimate for the terminal.Type: GrantFiled: April 29, 2013Date of Patent: May 6, 2014Assignee: QUALCOMM IncorporatedInventors: Petru Cristian Budianu, Dhananjay Ashok Gore, Alexei Yurievitch Gorokhov
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Patent number: 8718127Abstract: Apparatus and methods are disclosed, such as those involving a receiver device. One such apparatus includes an equalizer configured to process an input signal transmitted over a channel. The equalizer includes a first node configured to receive the input signal; a second node; and a programmable gain amplifier (PGA) having an adjustable gain. The PGA has an input electrically coupled to the first node, and an output electrically coupled to a third node. The equalizer also includes a high pass filter (HPF) having an input electrically coupled to the third node, and an output electrically coupled to the second node; and a control block configured to adjust one or more of the PGA or the HPF at least partly in response to a PGA output signal from the PGA or an HPF output signal from the HPF.Type: GrantFiled: August 2, 2011Date of Patent: May 6, 2014Assignee: Analog Devices, Inc.Inventors: Pablo Acosta-Serafini, Kimo Tam
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Patent number: 8718207Abstract: The present invention relates to an adaptive, high cost-performance efficient, and power-saving receiving method used for wireless communication systems, such as but not limited to Bluetooth (BT) system, in particular to a method which can detect the presence or absence of the adjacent channel interference (ACT) before the scheduled starting time for receiving a Bluetooth packet, and accordingly set the receiver configurations including the filter's pass-band bandwidth (BW), filter's order, the sampling rate or the number of analog-to-digital-converter (ADC) output bits, and the automatic-gain-control (AGC) algorithm to determine the low noise amplifier (LNA) and variable gain amplifier (VGA) settings.Type: GrantFiled: May 8, 2012Date of Patent: May 6, 2014Assignee: ISSC Technologies Corp.Inventors: Jeng-Hong Chen, Peng-Sen Chen, Hsiang-Te Ho, Kuang-Hu Huang, Zhi-Qing Huang, Chin-Chang Chang
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Patent number: 8711959Abstract: The present invention provides an apparatus and method for estimating a frequency offset which are robust against non-Gaussian noise. In a frequency offset estimation method of an Orthogonal Frequency Division Multiplexing (OFDM) system using a training symbol, the method includes receiving a reception signal, setting a specific initial frequency offset corresponding to the reception signal, and calculating a log-likelihood function based on a Complex Isotropic Symmetric ? Stable (CIS?S) probability density function obtained by modeling non-Gaussian noise included in the reception signal and estimating an optimum frequency offset based on the log-likelihood function and the initial frequency offset through a Maximum Likelihood Estimator (MLE). Accordingly, in a non-Gaussian noise environment, frequency offset estimated performance can be improved as compared with a conventional method in which noise is assumed to be a normal distribution.Type: GrantFiled: September 10, 2012Date of Patent: April 29, 2014Assignee: Research & Business Foundation Sungkyunkwan UniversityInventors: Youngpo Lee, Seokho Yoon
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Patent number: 8712358Abstract: A system for receiving an analogue signal e includes amplifying and digitizing the signal in order to obtain a digitized signal en, a power inversion module, the module determining an inversion gain g2, this gain being applied to the digitized signal en, an automatic gain control AGC loop adapting the power of the signal e before digitization, the input signal of the AGC loop being a function of the inversion gain g2.Type: GrantFiled: June 8, 2012Date of Patent: April 29, 2014Assignee: THALESInventors: Nicolas Martin, Jean-Michel Perre, David Depraz
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Publication number: 20140112421Abstract: Disclosed is a communication apparatus including an amplification part and a transient characteristics control part. The amplification part is configured to amplify a signal level of a received signal. The transient characteristics control part is configured to control transient characteristics of the amplification part.Type: ApplicationFiled: October 9, 2013Publication date: April 24, 2014Applicant: Sony CorporationInventor: Koichi Ooya
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Patent number: 8706064Abstract: A system and method improve amplifier efficiency of operation relative to that of an amplifying transistor with a fixed bias current. A power level representing a level of transmission power from an amplifier circuit and an indicator of amplifier circuit operation are provided. The indicator is at least one of channel, channel bandwidth, out-of band spectral requirements, spectral mask requirements, error vector magnitude, modulation rate, and modulation type. The amplifying transistor is biased with a bias current that is determined based at least in part on the power level and the indication where the bias current is different for channels at an edge of a channel band than for channels nearer a center of the channel band.Type: GrantFiled: February 27, 2013Date of Patent: April 22, 2014Assignee: SiGe Semiconductor, Inc.Inventors: Alan J. A. Trainor, Grant Darcy Poulin, Craig Joseph Christmas
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Patent number: 8705671Abstract: Various methods for performing amplifier gain compensation to correct for variations in temperature are provided. One example method includes modifying a gain adjustment value based on a current temperature reading, receiving a signal, applying a gain adjustment to the signal based on the gain adjustment value, comparing the gain adjusted signal to a plurality of thresholds to generate respective comparison outputs, and selecting one of the comparison outputs for use in determining content and timing information of the received signal. Related systems and apparatuses are also provided.Type: GrantFiled: July 15, 2011Date of Patent: April 22, 2014Assignee: Zebra Enterprise Solutions Corp.Inventors: Aitan Ameti, Edward A. Richley
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Patent number: 8705595Abstract: Devices and methods related to devices capable to perform digital output power measurement besides attenuation control are provided. A device includes a digital signal processing unit, a transmitter and a feedback receiver. The digital signal processing unit is configured to control attenuation along a transmission path and a feedback path based on a comparison of a power of a digital input signal with a raw power of a corresponding digital feedback signal, and to calculate an output power value of an analog RF signal to be broadcasted, using the raw power of the digital feedback signal and one or more feedback gain factors related to gain in the feedback receiver.Type: GrantFiled: May 6, 2011Date of Patent: April 22, 2014Assignee: Telefonaktiebolaget L M Ericsson (publ)Inventors: Kris Bailey, Slim Ben Ghalba, Peter Zahariev Rashev
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Patent number: 8705672Abstract: A receiver has an input and a decision feedback equalizer (DFE). The DFE couples to the receiver input and has at least one tap coefficient. An input signal, having a first amplitude level insufficient to cause significant non-linear distortion in the receiver, is applied to the receiver input. After the DFE adapts to the applied input signal having the first amplitude level by adjusting the at least one tap coefficient, the adaptation process is stopped. Then the at least one tap coefficient is scaled by a factor ? and the amplitude of input signal is adjusted to a second amplitude level greater than the first amplitude level by the scale factor ?. Although the second amplitude level might be sufficient to cause significant non-linear distortion in the receiver, the scaled tap coefficient has the correct values for proper DFE operation in the presence of the non-linear distortion.Type: GrantFiled: September 26, 2011Date of Patent: April 22, 2014Assignee: LSI CorporationInventors: Amaresh Malipatil, Mohammad Mobin, Pervez Aziz, Ye Liu
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Publication number: 20140105336Abstract: An exemplary embodiment disclosed comprises a mixer having a plurality of input leads; a first degenerative impedance element coupled to a first input lead of the mixer; a second degenerative impedance element coupled to a second input lead of the mixer; and a local oscillator (LO) system comprising a plurality of duty cycle modes to generate a LO signal for the mixer, the local oscillator system operates in a first duty cycle based on a first gain state of the mixer, and in a second duty cycle based on a second gain state of the mixer.Type: ApplicationFiled: December 18, 2013Publication date: April 17, 2014Applicant: QUALCOMM INCORPORATEDInventors: Junxiong Deng, Aristotele Hadjichristos, Aleksandar Tasic, Fredric Bossu
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Patent number: 8699638Abstract: The present invention discloses a method for implementing automatic frequency control, and an apparatus thereof. The method discloses: calculating a correlation value of common pilot symbols in a reception signal of each path and a frequency offset value, calculating a combined frequency offset value according to the frequency offset value of each path, and determining, according to the combined frequency offset value, a frequency offset adjustment value for a voltage controlled oscillator, a frequency offset adjustment value for overall reception signals and a frequency offset adjustment value for the reception signal of each path. The present invention selects a method of small-scope frequency offset estimation, which makes frequency offset estimation more accurate.Type: GrantFiled: September 28, 2010Date of Patent: April 15, 2014Assignee: ZTE CorporationInventor: Liqiang Yi
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Publication number: 20140098912Abstract: A receiver in a communication system is provided that includes a synchronization module and a channel estimator. The synchronization module is configured to identify an end of a cyclic prefix (CP) in a received signal using slope detection by monitoring a detection metric threshold in the received signal. The channel estimator is configured to estimate a complex noise variance using guard band subcarriers.Type: ApplicationFiled: September 30, 2013Publication date: April 10, 2014Applicant: Samsung Electronics Co., LTDInventors: Bei Yin, Gary Xu, Eran Pisek, Shadi Abu-Surra, Thomas Henige, Zhouyue Pi
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Patent number: 8693596Abstract: Apparatus and methods calibrate and control detector gain in a Mueller-Muller timing detector. A main signal path includes a Mueller-Muller based timing error detector (MM TED). The main signal path generates a main error signal for clock recovery. A secondary signal path that includes a secondary MM TED. Each signal path samples soft symbols from a received signal. The sampling of the secondary MM TED is deliberately offset in time. A scale factor applied to the main error signal and to a secondary error signal is adaptively adjusted based on a comparison between the main error signal and the secondary error signal.Type: GrantFiled: July 13, 2012Date of Patent: April 8, 2014Assignee: PMC-Sierra, Inc.Inventors: William D. Warner, Anthony Eugene Zortea
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Patent number: 8693595Abstract: The present invention relates to an adaptive, cost-performance efficient, power-saving apparatus for wireless communication systems, such as but not limited to Bluetooth (BT) receivers, and in particular to a packet-based receiver's decoding algorithm which can detect the presence or absence of the adjacent channel interference (ACI) before the scheduled starting time for receiving a Bluetooth packet, and accordingly set the receiver configurations including the filter's pass-band bandwidth (BW), filter's order, the sampling rate, the number of analog-to-digital-converter (ADC) output bits, and the automatic-gain-control (AGC) algorithm unit to determine the low noise amplifier (LNA) and variable gain amplifier (VGA) settings.Type: GrantFiled: May 8, 2012Date of Patent: April 8, 2014Assignee: ISSC Technologies Corp.Inventors: Jeng-Hong Chen, Peng-Sen Chen, Hsiang-Te Ho, Kuang-Hu Huang, Zhi-Qing Huang, Chin-Chang Chang
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Patent number: 8693594Abstract: The receiver includes a first arithmetic circuit that calculates a first mean value of the third signal in a preset first measurement setting period. The receiver includes a second arithmetic circuit that calculates a second mean value of the fourth signal in the first measurement setting period. The receiver includes a control circuit that controls the first arithmetic circuit and the second arithmetic circuit, changes the first set value according to the first mean value, and changes the second set value according to the second mean value.Type: GrantFiled: March 19, 2012Date of Patent: April 8, 2014Assignee: Kabushiki Kaisha ToshibaInventor: Hiroshi Yoshida
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Patent number: 8693592Abstract: An AGC unit starts a gain control of the variable gain amplifying unit when a bit saturation occurs in the digital baseband signal output from the A/D converting unit, and starts a gain control of the variable gain amplifying unit when a detection of STS from the digital baseband signal output from the A/D converting unit is started. The AGC unit performs the gain control of the variable gain amplifying unit once when the detection of STS is started, and performs the gain control of the variable gain amplifying unit twice when the bit saturation occurs, namely a larger number of times than when the detection of STS is started.Type: GrantFiled: March 10, 2008Date of Patent: April 8, 2014Assignee: Panasonic CorporationInventors: Koji Imamura, Naganori Shirakata, Shuya Hosokawa, Kenji Miyanaga
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Patent number: 8693593Abstract: Methods and apparatus are provided for automatic gain control in a receiver using samples taken at a desired sampling phase and target voltage level. The gain of a received signal is adjusted by obtaining a plurality of samples of the received signal substantially at a desired sampling phase (such as a center of a given unit interval), wherein at least one of the samples is taken substantially at a target voltage level; comparing the plurality of samples to determine whether the received signal has an amplitude that is substantially equal to the target voltage level; and adjusting a receiver gain based on whether the received signal amplitude is substantially equal to the target voltage level. The comparison can comprise the evaluation of a logic function, such as an exclusive OR function. The comparison can be performed over a plurality of samples to obtain an average gain update decision.Type: GrantFiled: December 30, 2010Date of Patent: April 8, 2014Assignee: LSI CorporationInventors: Mohammad S. Mobin, Matthew Tota, Mark Trafford
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Patent number: 8687724Abstract: A method for performing a fast multiple-subcarrier-joint-modulation (MSJM) precoding. The method comprises grouping input information bits into bit blocks; converting the bit blocks into bit vectors; mapping a first group of bits of each bit vector to a real dimension of symbols in a symbol vector; mapping a second group of bits of each bit vector to an imaginary dimension of symbols in the symbol vector, wherein the mapping of the real dimension and the mapping of imaginary dimension are performed simultaneously; and modulating symbol vectors into data subcarriers.Type: GrantFiled: March 9, 2009Date of Patent: April 1, 2014Assignee: Koninklijke Philips N.V.Inventors: Dong Wang, Yue Shang
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Publication number: 20140086370Abstract: A system provides closed-loop gain control in a WCDMA mode and open loop control in an EDGE/GSM mode. Gain control is distributed across analog devices and a digital scaler in a wireless receiver. In the WCDMA mode, a loop filter generates an error signal that is forwarded to analog and digital control paths. The analog control path includes a first adder, a programmable hysteresis element, and a lookup table. The analog control signal is responsive to thresholds, which when used in conjunction with a previous gain value determine a new gain value. The digital control path includes a second adder, a programmable delay element, and a converter. A control word is responsive to a difference of the error signal, a calibration value, and the analog control signal. Blocker detection is provided in the WCDMA mode of operation. A controller sets system parameters using a state machine.Type: ApplicationFiled: September 16, 2013Publication date: March 27, 2014Applicant: SKYWORKS SOLUTIONS, INC.Inventors: Jaleh Komaili, John E. Vasa, Thomas Obkircher
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Patent number: 8681846Abstract: Systems and methods for measuring transmitter and/or receiver I/Q impairments are disclosed, including iterative methods for measuring transmitter I/Q impairments using shared local oscillators, iterative methods for measuring transmitter I/Q impairments using intentionally-offset local oscillators, and methods for measuring receiver I/Q impairments. Also disclosed are methods for computing I/Q impairments from a sampled complex signal, methods for computing DC properties of a signal path between the transmitter and receiver, and methods for transforming I/Q impairments through a linear system.Type: GrantFiled: May 3, 2013Date of Patent: March 25, 2014Assignee: National Instruments CorporationInventors: Stephen L. Dark, Christopher J. Behnke
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Publication number: 20140079165Abstract: A multiple-input-multiple-output (MIMO) receiving system configured for receiving multiple transmission layers is provided herein. The system includes a plurality of beamformed tunable receiving antennas configured to receive a plurality of transmitted layers; and a control module configured to select for the beamformed antennas a single set of discrete weights for tuning said antennas for all of the transmitted layers so that the weights are selected for optimal performance of said receiving system, wherein said selection is carried out based on an extended Maximal Ratio Combining (MRC) metric or other quality metric measured by the MIMO baseband module, and using said measured metric separately for each beamformed antenna to determine gain or attenuation independently of phase selection.Type: ApplicationFiled: November 22, 2013Publication date: March 20, 2014Applicant: Magnolia Broadband Inc.Inventors: Kenneth KLUDT, Eduardo ABREU, Haim HAREL
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Publication number: 20140079141Abstract: A method of removing a signal from among received signals, the method including: filtering the received signals; detecting a time band of the filtered received signals where an energy value of the filtered received signals exceeds a reference energy value; and applying a gain value to one or more received signals, from among the received signals, in the detected time band.Type: ApplicationFiled: November 18, 2013Publication date: March 20, 2014Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Beak-kwon SON, Dong-won LEE, Jae-Hyun KIM, Sang-ki KANG
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Patent number: 8676141Abstract: A power control method in a mobile station having at least two antennas. The mobile station operates in a receive-diversity state in which the mobile station wirelessly receives communications with multiple antennas. The mobile station determines a relative gain of operating in the receive-diversity state versus operating in a non-receive-diversity state in which the mobile station wirelessly receives communications with one antenna rather than with multiple antennas. The mobile station uses the determined gain as a basis to set one or more power characteristic(s). The one or more power characteristic(s) may include (i) an initial power control setpoint for use by the mobile station to evaluate strength of received transmissions and (ii) an initial power level at which a remote entity transmits to the mobile station.Type: GrantFiled: October 15, 2010Date of Patent: March 18, 2014Assignee: Sprint Spectrum L.P.Inventor: Sachin R. Vargantwar
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Patent number: 8675789Abstract: A receiver comprising: one or more variable gain elements; an automatic gain control (AGC) for controlling a gain of one or more of the one or more the variable gain elements; and a frame detector configured to detect the presence of a frame in a signal received by the receiver and to output a signal to the AGC on detection of a data frame, wherein the AGC is configured to estimate a signal to noise ratio (SNR) of the received signal on receiving an input signal from the frame detector, to calculate a SNR margin between the estimated SNR and a target SNR and to adjust the gain of one or more of the one or more variable gain elements to maintain a positive SNR margin such that in the event of interference with the received signal the one or more variable gain elements do not saturate.Type: GrantFiled: April 23, 2012Date of Patent: March 18, 2014Assignee: Cambridge Silicon Radio LimitedInventor: Olivier Seller
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Patent number: 8676146Abstract: An electronic apparatus includes: a first integrated circuit including an internal component section capable of being adjusted with adjustment data, a nonvolatile memory in which beforehand acquired adjustment data of a result of adjustment carried out in advance for the internal component section are stored, and an interface section having a data transfer function of transferring the beforehand acquired adjustment data read out from the nonvolatile memory to the outside and a data storage function of storing actual use adjustment data sent thereto from the outside and supplying the stored actual use adjustment data to the internal component section; and a second integrated circuit including a signal processor, to which the interface section of the first integrated circuit is connected.Type: GrantFiled: March 6, 2009Date of Patent: March 18, 2014Assignee: Sony CorporationInventors: Naruhiro Yoshida, Hiroshi Aoki, Takahiro Okada, Tatsuo Shinbashi, Nobuo Kato, Taiwa Okanobu
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Patent number: 8670510Abstract: Aspects of a method and system for channel estimation in a MIMO communication system with multiple RF chains for WCDMA/HSDPA may comprise receiving a plurality of communication signals from a plurality of transmit antennas. A plurality of vectors of baseband combined channel estimates may be generated based on phase rotation of the received plurality of communication signals. A matrix of processed baseband combined channel estimates may be generated based on the generated plurality of vectors of baseband combined channel estimates. A plurality of amplitude and phase correction signals may be generated based on the generated plurality of vectors of baseband combined channel estimates. An amplitude and a phase of at least a portion of the received plurality of communication signals may be adjusted based on the generated plurality of amplitude and phase correction signals, respectively.Type: GrantFiled: April 8, 2013Date of Patent: March 11, 2014Assignee: Broadcom CorporationInventors: Mark Kent, Vinko Erceg, Uri M. Landau, Pieter van Rooyen
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Publication number: 20140056395Abstract: A method of performing Automatic Gain Control, AGC, in a receiver of a device is provided. The device is served on a serving carrier of a multi-carrier communication network. Measurement gaps are scheduled on the serving carrier for inter-carrier measurements on a non-serving carrier. The method comprises the step of determining a first time interval, in which a predefined signal portion is transmitted on the non-serving carrier; the step of estimating, for the first time interval, received signal power on the non-serving carrier; the step of computing a receiver gain based on the estimate signal power; the step of performing, over a second time interval, an inter-carrier measurement on the non-serving carrier; and the step of applying the receiver gain to the receiver after the second time interval.Type: ApplicationFiled: April 13, 2012Publication date: February 27, 2014Applicant: Telefonaktiebolaget L M Ericsson (Publ)Inventors: Peter Alriksson, Joakim Axmon
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Patent number: 8660510Abstract: Provided is a receiving apparatus for processing an analog baseband signal in an information terminal that communicates using a dielectric. The receiving apparatus includes an electrode for receiving an electric-field signal; a first gain adjuster for gain adjustment by amplifying the received signal; a channel selection filter for selecting a signal corresponding to a receive channel bandwidth from the gain-adjusted signal; a second gain adjuster for gain adjustment by amplifying the selected signal; a comparator for converting a signal output from the second gain adjuster into a digital signal; an oversampler for oversampling the digital signal at a frequency fClock higher than a receive channel frequency fSignal; a demodulator for demodulating the oversampled signal; and a clock generator for providing necessary a clock signal to the oversampler and the demodulator.Type: GrantFiled: May 7, 2010Date of Patent: February 25, 2014Assignee: Samsung Electronics Co., LtdInventors: Seong-Jun Song, Sang-Yun Hwang, Chul-Jin Kim, Jong-Rim Lee, Hyun-Kuk Choi, Seok-Yong Lee
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Patent number: 8660221Abstract: The present invention discloses apparatus and method for fast and robust automatic gain control (AGC). By using the power statistics and/or the amplitude statistics of multiple pairs of signed ADC outputs, the additional gain control can be determined and included in a statistics-aided AGC to successfully complete the AGC function for a received signal having a dynamic range up to 100 dB within a few micro-seconds.Type: GrantFiled: June 14, 2012Date of Patent: February 25, 2014Assignee: ISSC Technologies Corp.Inventors: Jeng-Hong Chen, Huei-Ming Yang, Chih-Ching Huang
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Patent number: 8655295Abstract: According to one embodiment, a receiving apparatus includes a variable gain amplifier, comparator, and signal processor. The comparator compares a signal level of the second signal with a first threshold to generate a third signal, a signal level of the third signal being set to a high signal if the signal level of the second signal is greater than the first threshold. The signal processor determines presence of a signal if a rate of high signals in third signals for a period is greater than a second threshold. The second threshold is set to a first value when the control of the gain is performed and set to a second value when the demodulation processing is performed. The first value is greater than the second value.Type: GrantFiled: February 10, 2012Date of Patent: February 18, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Tsuyoshi Kogawa, Koji Ogura, Shoji Otaka, Hiroaki Ishihara
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Patent number: 8654904Abstract: In one embodiment, a receiver comprises an automatic gain controller (AGC), an equalizer, a controller, and a register interface. The AGC makes gain adjustments to compensate for changes in the average amplitude of a received signal. The equalizer has a coefficient updater that calculates coefficients and a finite impulse response (FIR) filter that applies the coefficients to the received signal to generate an equalized signal. During gain adjustments by the AGC, the register interface provides a weight freeze signal to the coefficient updater, which subsequently freezes the updating of the coefficients for a freeze duration period. Then, register interface provides a scaling factor, generated by the controller based on the size of the gain adjustment, to the coefficient updater. At the end of the freeze period, coefficient updater applies the scaling factor to the coefficients and unfreezes the coefficient updating.Type: GrantFiled: October 9, 2007Date of Patent: February 18, 2014Assignee: Agere Systems LLCInventors: Uwe Sontowski, Dominic W. Yip
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Publication number: 20140044158Abstract: Apparatus and methods disclosed herein perform gain, clipping, and phase compensation in the presence of I/Q mismatch in quadrature RF receivers. Gain and phase mismatch are exacerbated by differences in clipping between I & Q signals in low resolution ADCs. Signals in the stronger channel arm are clipped differentially more than weaker signals in the other channel arm. Embodiments herein perform clipping operations during iterations of gain mismatch calculations in order to balance clipping between the I and Q channel arms. Gain compensation coefficients are iteratively converged, clipping levels are established, and data flowing through the network is gain and clipping compensated. A compensation phase angle and phase compensation coefficients are then determined from gain and clipping compensated sample data. The resulting phase compensation coefficients are applied to the gain and clipping corrected receiver data to yield a gain, clipping, and phase compensated data stream.Type: ApplicationFiled: August 13, 2012Publication date: February 13, 2014Inventors: Ganesan Raghu, Bijoy Bhukania, Jaiganesh Balakrishnan
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Publication number: 20140037030Abstract: An automatic gain control loop disposed in a receiver is adapted to compensate for varying levels of out of band interference sources by adaptively controlling the gain distribution throughout the receive signal path. One or more intermediate received signal strength indicator (RSSI) detectors are used to determine a corresponding intermediate signal level. The output of each RSSI detector is coupled to an associated comparator that compares the intermediate RSSI value against a corresponding threshold. The take over point (TOP) for gain stages is adjusted based in part on the comparator output values. The TOP for each of a plurality of gain stages may be adjusted in discrete steps or continuously.Type: ApplicationFiled: October 2, 2013Publication date: February 6, 2014Applicant: MaxLinear, Inc.Inventors: Curtis LING, Madhukar REDDY, John WETHERELL
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Publication number: 20140037031Abstract: Apparatus and methods are disclosed, such as those involving a receiver device. One such apparatus includes an equalizer configured to process an input signal transmitted over a channel. The equalizer can include a programmable gain amplifier (PGA) block which includes an input node configured to receive the input signal; an output node; and a programmable gain amplifier (PGA). The PGA amplifies the input signal with an adjustable gain. The PGA block also includes a gain control block having an input electrically coupled to the input node. The gain control block is configured to adjust the gain of the PGA at least partly in response to the input signal from the input node such that the PGA generates an output signal with a substantially constant amplitude envelope to the output node.Type: ApplicationFiled: October 7, 2013Publication date: February 6, 2014Applicant: ANALOG DEVICES, INC.Inventors: Pablo Acosta-Serafini, Kimo Tam, Stuart McCracken, Daniel Mulcahy
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Patent number: 8644435Abstract: A method for remotely detecting electromagnetic interference on a data transmission line of a communication network includes measuring at a client site a noise power spectrum on the data transmission line as a function of frequency, for a frequency range. The noise is present when the data transmission line is not carrying a data signal. The method further includes forwarding the measured noise power spectrum to a remote computer at a network operator's site, determining periodicities in the measured power spectrum by the remote computer, and determining the switching frequency of a power supply unit at the client site by the remote computer based on periodicities in the power spectrum.Type: GrantFiled: April 26, 2011Date of Patent: February 4, 2014Assignee: Alcatel LucentInventors: Benoit Drooghaag, Arnaud Bertrand, Martin Dorme
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Patent number: 8644406Abstract: The present invention relates to a method of transmitting and receiving signals and a corresponding apparatus. One aspect of the present invention relates to a method of extracting PLP from data slices.Type: GrantFiled: May 12, 2009Date of Patent: February 4, 2014Assignee: LG Electronics Inc.Inventors: Woo Suk Ko, Sang Chul Moon
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Publication number: 20140029705Abstract: Briefly, in accordance with one embodiment, a method of adjusting for digital automatic gain control (DAGC) quantization error in a mobile station is as follows. A first DAGC value is stored before reception of one or more enhanced pilot signals. A second DAGC value is computed during reception of the one or more enhanced pilot signal. The first DAGC value is restored after reception of the one or more enhanced pilot signals is over. An advantage associated with this particular embodiment may include reduction in quantization error for digital automatic gain control.Type: ApplicationFiled: July 17, 2013Publication date: January 30, 2014Applicant: QUALCOMM IncorporatedInventors: Qiang Wu, Wanlun Zhao, Peter John Black
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Patent number: 8638888Abstract: One embodiment of the present invention relates to an analog correlation unit comprising a plurality of parallel correlation components configured to operating according to an advanced switched-capacitor low pass filter principle that increases coding gain of the unit. Each correlation component comprises a sampling stage and a correlation stage. The sampling stage may comprise a switched capacitor configured to sample a received baseband signal to determine a value (e.g., polarity) of the baseband signal. The sampled baseband signal is provided to the correlation stages, which may respectively comprise a plurality of switched integrators configured to selectively receive and integrate the sampled baseband signal over time depending upon values (e.g., polarity) of the correlation code to generate voltage potential values. The analog correlation result is evaluated by a comparison of an adjustable threshold voltage with the difference between the output voltage potential values.Type: GrantFiled: July 21, 2011Date of Patent: January 28, 2014Assignee: Infineon Technologies AGInventors: Christian Hambeck, Stefan Mahlknecht, Thomas Herndl, Franz Darrer, Jakob Jongsma
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Patent number: 8638883Abstract: A method includes receiving a signal using a direct conversion receiver, while the receiver is set at a gain that is selected from a range of possible gain values. Multiple DC offset correction values are provided for use by a DC offset cancellation loop, each DC offset correction value being associated with a respective sub-range of the range of the possible gain values. A DC offset correction value is selected from among the multiple DC offset correction values based on the gain to which the receiver is set. A DC offset in the signal is canceled by setting the DC offset cancellation loop to the selected DC offset correction value.Type: GrantFiled: February 1, 2011Date of Patent: January 28, 2014Assignee: Marvell World Trade Ltd.Inventors: Rony Ashkenazi, Alexander Zaslavsky, Gregory Uehara, Brian Brunn
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Patent number: 8639205Abstract: An exemplary embodiment disclosed comprises a mixer having a plurality of input leads; a first degenerative impedance element coupled to a first input lead of the mixer; a second degenerative impedance element coupled to a second input lead of the mixer; and a local oscillator (LO) system comprising a plurality of duty cycle modes to generate a LO signal for the mixer, the local oscillator system operates in a first duty cycle based on a first gain state of the mixer, and in a second duty cycle based on a second gain state of the mixer.Type: GrantFiled: March 20, 2008Date of Patent: January 28, 2014Assignee: QUALCOMM IncorporatedInventors: Junxiong Deng, Aristotele Hadjichristos, Aleksandar Tasic, Frederic Bossu
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Patent number: 8638835Abstract: A wireless repeater incorporates a gain management block to implement a multi-parameter gain management algorithm. The gain management algorithm receives gain settings from at least a gain control metric for stability and output signal quality and signal headroom values associated with circuitry of the repeater. The gain management block provides secure and robust boot-up of the repeater as well as oscillation detection and prevention. Furthermore, the gain management block implements repeater stability control, output signal-to-noise level control, uplink and downlink gain balance control and compensation for device constraints.Type: GrantFiled: December 6, 2011Date of Patent: January 28, 2014Assignee: Qualcomm IncorporatedInventors: Michael Mao Wang, Gwendolyn Denise Barriac, Dhananjay Ashok Gore, Tao Tian
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Patent number: 8638249Abstract: In accordance with an embodiment, a method includes determining an amplitude of an input signal provided by a capacitive signal source, compressing the input signal in an analog domain to form a compressed analog signal based on the determined amplitude, converting the compressed analog signal to a compressed digital signal, and decompressing the digital signal in a digital domain to form a decompressed digital signal. In an embodiment, compressing the analog signal includes adjusting a first gain of an amplifier coupled to the capacitive signal source, and decompressing the digital signal comprises adjusting a second gain of a digital processing block.Type: GrantFiled: April 16, 2012Date of Patent: January 28, 2014Assignee: Infineon Technologies AGInventors: Michael Kropfitsch, Jose Luis Ceballos
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Patent number: 8630821Abstract: System and method for testing a high speed data path without generating a high speed bit clock, includes selecting a first high speed data path from a plurality of data paths for testing. Coherent clock data patterns are driven on one or more of remaining data paths of the plurality of data paths, wherein the coherent clock data patterns are in coherence with a low speed base clock. The first high speed data path is sampled by the coherent clock data patterns to generate a sampled first high speed data path, which is then tested at a speed of the low speed base clock.Type: GrantFiled: July 25, 2011Date of Patent: January 14, 2014Assignee: QUALCOMM IncorporatedInventors: Miao Li, Xiaohua Kong, Nam V. Dang, Cheng Zhong
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Publication number: 20140010333Abstract: A method is provided for process, voltage, temperature (PVT) stable transfer function calibration in a differential amplifier. The gain resistors of a differential amplifier are initially selected to achieve a flat amplitude transfer function in the first frequency band. After calibration, the degeneration capacitor is connected and tuned until a peaked amplitude transfer function is measured, which is resistant to variations in PVT. As an alternative, the degeneration capacitor is not disconnected during initial calibration. Then, the gain resistors and the degeneration capacitor values are selectively adjusted until the first peaked amplitude transfer function is obtained. The peaked amplitude transfer function remains even more stable to variations in PVT than the flat amplitude calibration method.Type: ApplicationFiled: September 9, 2013Publication date: January 9, 2014Applicant: Applied Micro Circuits CorporationInventor: Hanan COHEN
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Patent number: 8626094Abstract: It has now been found that in some transmitter implementations which transmit multiple code channels, for example CDMA transmitters, the observed power for each code channel at the output relative to the other code channels is dependent upon the total transmit power due to non-linearities in the transmitter. Methods and apparatus are provided which use pre-set digital gains or digital gain adjustments to compensate for the non-linearities as a function of total transmit power such that at the output, the desired relative powers are observed.Type: GrantFiled: January 28, 2013Date of Patent: January 7, 2014Assignee: BlackBerry LimitedInventors: Xin Jin, Qingzhong Jiao, Wen Zhao
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Patent number: 8626002Abstract: A method and system for optoelectronic receivers for uncoded data are disclosed and may include amplifying received electrical signals in a signal amplifier comprising differential gain stages with signal detectors coupled to the outputs. First and second output voltages may be tracked and held utilizing the signal detectors. A difference between the tracked and held value may be amplified in a feedback path of the gain stage, which enables the dynamic configuration of a decision level. The received electrical signals may be generated from an optical signal by a PIN detector, an avalanche photodiode, or a phototransistor. The electrical signal may be received from a read channel. The feedback path may comprise digital circuitry, including an A/D converter, a state machine, and a D/A converter. The detectors may comprise envelope detectors utilized to detect maximum or minimum voltages. The signal amplifier may be integrated in a photonically-enabled CMOS chip.Type: GrantFiled: January 15, 2013Date of Patent: January 7, 2014Assignee: Luxtera, Inc.Inventor: Daniel Kucharski